By Alyah Khan

A debate is emerging about the potential use of genetically modified (GM) mosquitoes to combat dengue in the United States and in other countries around the world. Most recently, news out of Brazil indicated that the country plans to breed GM mosquitoes to stop the spread of dengue.
Our previous blog post examined Brazil’s new anti-dengue strategy. It also mentioned the British biotechnology company, Oxitec, which has “developed a method to modify the genetic structure of the male Aedes mosquito, essentially transforming it into a mutant capable of destroying its own species.”
An article in Reuters further explained that Oxitec’s GM technique “involves introducing sterile males into the mosquito population so they mate with females thereby reducing the overall birth rate.” Successful outdoor trials of this technique in Brazil, the Cayman Islands and Malaysia have seen an 80 percent reduction in the Aedes aegypti population, according to Oxitec.
Additionally, research published in 2011 revealed that GM males mated successfully with wild females and could reduce the number of disease-carrying mosquitoes, according to a report by the BBC.
As Brazil moves forward with its plan, experts are weighing in on the possible benefits and consequences of using GM mosquitoes in the global fight against dengue.
Hank Campbell, writing for the Los Angeles Times, brushed off concerns about the use of “mutant mosquitoes” in the Florida Keys. Campbell wrote, “Concern about the mosquitoes that prevent the disease, compared to the dangers of the disease or even the pesticides used to kill mosquitoes, is unwarranted. These mosquitoes can save lives without harmful chemicals, and they can’t harm us. This is a win for everyone.”
But, critics worry that eradicating one species of mosquitoes could have “unintended consequences on the food chain and ecosystem,” according to the Reuters article. Florida residents, for example, have launched a petition (with over 100,000 signatures) to stop experts from using GM mosquitoes in their state. The U.S. Food and Drug Administration must approve the Oxitec experiment before it can proceed.
There are clearly proponents both for and against the use of GM mosquitoes. Yet, even those within Oxitec recognize that GM mosquitoes aren’t a “magic bullet” that will solve the challenge of dengue.
Luke Alphey, Oxitec’s chief scientific officer and a visiting professor at Oxford University, told the BBC that GM mosquitoes should be one component of an integrated program against dengue.
Besides what’s going on with Oxitec, there have also been reports about Scott O’Neill’s work in Australia. NPR highlighted O’Neill’s big idea, which is to infect mosquitoes with naturally occurring bacteria called Wolbachia. Wolbachia-infected mosquitoes can’t carry the dengue virus. However, O’Neill has said his data is still preliminary and the ultimate effectiveness of this experiment is unknown.
The results of the efforts in Brazil, Australia and possibly Florida remain to be seen. We will continue to monitor what will surely be an ongoing debate about the use of GM mosquitoes in the struggle to control dengue. To stay up-to-date on the latest dengue news, be sure to follow us on Twitter @preventdengue.